MaterialSteel High carbon steel, high quality material to avoid during use. General Use These extenders, adapters and reducers are designed for Impact use and feature spring-loaded detent balls to lock sockets securely, while through-holes at the drive end of adapters and reducers lock onto the drive shaft. convenience no matter which tool you choose to use. Ideal for DIY, household maintenance and most general repairs High QualityExtension adapters are made of heat treated chrome vanadium steel with a black oxide coating. Adapters and reducers are premium high-strength chrome steel with a manganese phosphate coating to help resist rust and corrosion. a lifetime of use. Widely ApplicationSuitable for 1/4 inch quick change chuck systems or directly into the drill chuck. Any cordless electric drill in a nut driver. Convenient for quick driving of nuts, bolts and fasteners etc. The spring-loaded ball bearing on the head holds the sockets securely. After-sales ServiceWe will provide you with the friendliest customer service. welcome to contact us If you have any issues with your impact socket extension and adapter kit, simply contact customer service for assistance, troubleshooting, replacement or a refund. Feature: 1. Color coded for easy recognition. 2. Spring-loaded ball for secure grip retention, so sockets snap into place and won't slip. 3. The 1/4 inch hex shank prevents stripping during high speed drilling operation. 4. Extra strong heat treated chrome vanadium steel for normal and impact use 5.Adapts sockets to drills and drivers, turns any electric or cordless drill into a nut driver. 6. Converts all power drills into speed plug drivers. 7. Use with a hand-grip screwdriver or battery or power tool. Material: Chrome Vanadium Steel (CR-V) Size:< /p> 1/4*1/4*65mm Length ------ 1/4" shank can be converted to 6.35mm square head 3/8* 1/4*65mm Length------1/4" shank can be converted to 9.4mm square head 1/2*1/4*72mm Length--- --- 1/4" shank can be converted to 12.6mm square head Adapter set, 4 pieces Size : 1/2"------ female square converted to 3/8" male 3/8"------ female square converted to 1/ 4" male 3/8"------ female square convert to 1/2" male 1/4"------ female square convert to 3/8" male